Figure 5

NDRG2 represses ASCT2 through the induction of Fbw7-dependent c-Myc degradation. (A-D) We gained c-Myc function through overexpression in NDRG2-overexpressing MC3 cells. The indicated proteins levels (A), ASCT2 mRNA levels (B), c-Myc enrichment on ASCT2 promoter (C), and the activities of wild-type and E-box-mutant ASCT2 promoter (D) were determined respectively. (E) c-Myc mRNA levels were determined in MC3 cells with or without NDRG2 expression. (F) Levels of indicated protein expressions were determined in MC3 cells with or without NDRG2 expression, or NDRG2-overexpressed MC3 cells with Fbw7 knockdown. (G) MC3 cells with or without NDRG2 expression were treated with 20 µM MG132 for 2 h. Levels of indicated proteins were determined by western blot. (H-K) Levels of indicated proteins in indicated MC3 cells or MEF cells following 10 µg/ml CHX treatment for indicated time (H and J). c-Myc expression levels were further quantified by ImageJ and normalized to β-actin to determine the protein degradation rate (I and K). **, P <0.001.